Our invention pertains to enclosures for power plants or engines, such as those of earthmoving vehicles, and deals more specifically with such an enclosure capable of drastically attenuating the noise emanating from the power plant while admitting of sufficient airflow for its cooling.
Bulldozers and like earthmoving vehicles employ large internal combustion engines and associated power plant components which give off very substantial noise. The earthmoving industry has made various attempts to suppress the noise levels of such vehicle power plants. Most conventional attempts have taken the form of power plant enclosures with a variety of soundproofing facilities. Soundproof enclosures, however, inevitably run counter to another requirement of air cooling the engine. Diffuculties have been encountered in designing power plant enclosures meeting the self contradictory requirement of mitigating the noise levels of the power plant and providing sufficient cooling airflow for its normal operation.
Whitehurst et al. U.S. Pat. No. 3,866,580, dated Feb. 18, 1975, and Kraina U.S. Pat. No. 4,071,009, dated Jan. 31, 1978, are typical of conventional attempts at the provision of engine enclosures fulfilling the above self contradictory objective. These known devices seem to us to leave room for further refinement.